Solve for $x$ and $y$ using substitution. ${-5x+2y = -4}$ ${x = 2y-4}$
Explanation: Since $x$ has already been solved for, substitute $2y-4$ for $x$ in the first equation. ${-5}{(2y-4)}{+ 2y = -4}$ Simplify and solve for $y$ $-10y+20 + 2y = -4$ $-8y+20 = -4$ $-8y+20{-20} = -4{-20}$ $-8y = -24$ $\dfrac{-8y}{{-8}} = \dfrac{-24}{{-8}}$ ${y = 3}$ Now that you know ${y = 3}$ , plug it back into $\thinspace {x = 2y-4}\thinspace$ to find $x$ ${x = 2}{(3)}{ - 4}$ $x = 6 - 4$ ${x = 2}$ You can also plug ${y = 3}$ into $\thinspace {-5x+2y = -4}\thinspace$ and get the same answer for $x$ : ${-5x + 2}{(3)}{= -4}$ ${x = 2}$